Just about the cheapest mod you`ll see... *Update - Now with added boost*

I`m pretty sure it is, and as far as my thinking goes, surely there`s a max boost level, and fuelling alone can`t alter it?

It may well reach this full boost level sooner as a result, but only some sort of extra boost control (be it re-map ro manual adjuster) would actually up the boost levels?

Feel free to correct me on that, anyone.

 

For the 1k pot mod, is the wiring carrying much current? I found some speaker wire last night....!

 

V / R = Amps

(Volts divided by Restistance)

Accountants

My T4 is mechanical Diesel injection so i can't participate in this one chaps.

 

I've no idea what the actual numbers are! Especially with a resistor in circuit! Hence the Q.

 

Don't worry Chris any size will be fine above 0.5mm

a bit of Telephone cable would do 0.2mm just so you can get a good solder onto it.

For Diesel Injections Pump repairs and upgrades this is the man you need to use.

http://www.dieselbob.co.uk/injectionpumps.shtml

 

Stu

Whats the Part Number for your Injection Pump ?

0460 -

Why don't you also have the Circuit controlled via a micro switch activated by Full Throttle only .

 

I`ll have to get back to you on that one.

Yeah, seen that done, but I don`t like the idea of having to give it full throttle to get the effect, when it`s perfectly adequate at just half-throttle!

I could, of course, set a micro-switch at around half-throttle, but I`d still want it switchable for those occasions when I might want more throttle, but not the mod in effect, so it`d be pointless really.

 

It's all action down at Kitchen Tuning™ this evening





What's even better is I still haven't a clue how this works. Just copied the connections on Stu's build

Btw, attn diesel tuners: smoke tax is moving in on this mod. The 1k pot is up to 2.57 at Maplin now, up 4 pence, and what with the resistor and adjuster knob, I've be mortgaged out to the tune of 3.57

I reckon with the speaker wire, that'll be it!

 

Do you understand the principal of how a transformer works?

Got that? Right...

The plunger in the pump who`s position (ie, stroke) determines how much fuel is delivered has two coils arranged very simialr to a transformer, with the pluger acting as the core.

The plunger has a variable stroke to deliver varying amounts of fuel. The ECU determines the stroke dependant on load, temperature, etc.

Pin 1 on your 8-pin plug is voltage (without looking at the schematic assumed to be 12v), that powers the first (primary) coil. This induces a voltage in the second(ary) coil (very low, certainly no more than 5v). Since the plunger is pulsing at it`s given stroke, this voltage is a `pulse signal` that the ECU reads (from Pin 2) to determine the plunger`s stroke.

When the plunger moves to a longer/shorter stroke for more/less fuel delivery, it`s relative position to the primary coil changes, and so the induced voltage in the secondary coil changes correspondingly.

Pin 3 on the harness is just an earth, and by putting the resistor/potentiometer between this and Pin 2, you are effectively shortening the wavelength of the pulse signal going back to the ECU. The ECU reads this as being too short a stroke of the plunger for the other parameters it is reading, and so lengthens the stroke to compensate, thus delivering more fuel. And of course more fuel = more POWER!

Probably Londoners Tax!



Hopefully tomorrow I`ll be in receipt of one of these;



Combined with my New South boost gauge...



...I`ll soon be up at 18psi to compensate when the injectors are in (waiting for new seals, before swapping them in).

 

You can sand the old seals so they are nice and shiny, has worked for me in the past more than once.

Apparently chucking them in boiling water does the job too, not tried that though myself

 

For 44p each I figured new ones wouldn`t be a bank-breaker.

Just a p*sser that they`re are only three in the whole of Manchester today, so I won`t get them till Monday.

 

But its the 2 trips to the dealer, the phoning them up cos they don't phone you.

To be fair though, installing them is so easy, its worth trying first anyway. Just keep your fingers crossed that the come out ok and you don't need a slide hammer, the car isn't high mileage is it?

 

off the top of my head (without looking at the circults)

it basicly a mod that alters the feed back from the pump regarding IQ, hence chucking in a huge amount of fuel
the ECU even going back has 2 values, required IQ & actual IQ without taking the slight difference in injector sizes into account if the feedback is saying the IQ is 20mg but the mapped values requiring 25mg it will inject the difference until 25mg is achived

So what your doing is adding a switchable/adjustable map regarding IQ's, it's not perfect but it works!

 

True, but my dealers is only 5 minutes away, and I think the parts guy has my number on speed-dial.

I was looking at the current injectors the other day, and they look like their going to be a right pig to get out...



Might have to give them a blast of WD over the next few days, and hope it helps. Just ticked over 160k miles BTW.

Too slow, Chris!

 

[YOUTUBE]Zo6mc_z3aM0[/YOUTUBE]

http://www.youtube.com/watch?v=Zo6mc_z3aM0

Needless to say this injector ended up as scrap. Not only that, but the head had to come off! Almost 10kg on that improvised slide hammer! Tried using the engine crane, lifted the car up.

 

I'l be honest I am totally confused by what's going on with that fuel pump. Transistors are like electro-magnets on speed to me, and the notion of a plunger in a diesel pump when it runs off a pulley puts me into a flat spin!

I know we're meddling with the signal-in, so that's (unusually) where my level of understanding seems to be parking itself.

But the pot is worse. 7 connectors on it, I'm using 4... I know it's varying the leccy which is going through (volts/amps, I wouldn't know), and a resistor jammed across a circuit.

I'm sure a throttle pot is 3 wires, so 7 and there's far too much going on there.

Don't worry about trying to drum it into me, I'm just happy to put my hands up on this one and say "I'm sh|t at this" !!!

Probably why Crispy's talking about "IQ", and I've no idea what he means. When Crispy on occasion talks about Can-bus networks, I'm in real trouble! My electricz IQ is low!!!

Having said that, I maintain that I'm better than a friend of mine who was an analyst in the City, she (note) was writing stuff on Marconi, Siemens and other cos, investor buy/sell write ups, yet didn't know what a soldering iron was

 

Cripes! Hopefully it won`t get that bad on mine...

Knowing my luck the first three will come out like greased weasels, and the last one will be stuck like that.

 

A throttle pot is indeed three contacts (wires) and so is the one you are using... .

The other four are the contacts for the switch (a pair of normally open, and a pair of normally closed). Remember your switched potentiometer is two components in one.

IQ I would assume means `injected quantity`, ie; amount of fuel delivered.

In really simple terms; you are altering one of the ECUs measuring parameters to trick it into supplying more fuel than is actually required.

 

Ok, I'm now coping with the idea there are 2 components in one! Why is one wire to the fuel pump coming off the switch terminals (again, copied blindly here ) and the other pump wire coming off the pot? Seems like apples & pears

 

Page one... [**EDIT - Pin number annotations corrected**]



The switch and the pot being two seperate components need combining hence the `jumper wire` (or in your case the fixed resistor) is required to bring them together in the one circuit.

In other applications the switch could work one circuit, and the pot another completely seperately but worked at the same time.

You understand that pot is a variable resistor? And that a resistor effectively restricts flow of electricity? Think of how a fuel pressure regulator works - exactly the same.

In simply terms the pot is a strip (or coil on old types) that you feed electricity into. As you turn the knob you altering how much of the strip/coil it has to flow through. The more it has to flow the more it`s restricted.

The three contacts are essentially; two `ins`, and an `out`. The left hand `in` lets it flow through the full distance of the strip/coil before coming `out` of the middle contact (known as a `wiper`) So you start of with maximum restriction, and as you turn the knob, the middle contact moves making the distance less, and hence the restriction is less. (The right hand `in` works the opposite way, so we can ignore it for this.)




You have four contacts on the switch. One pair of the (`in` and `out`) will be `made` when the switch is in the `off` position, so you break the circuit when operate the switch. This is known as `normally closed`.

The more common state for a switch (like a light switch) is of course the opposite of that, known as `normally open`. It`s these two contacts that we are using here.

It`s a slightly odd arrangement since usually a switch with NO and NC contacts only has three contacts like this (`c` being the `common` contact);



But rest assured it works!


As to why one wire goes to the switch, and one goes to the pot look back at the diagram at the top;

What we are doing to trick the ECU is to effectively `bleed off` some of the `flow`. Electricity is always trying to flow to earth, and in the normal scheme of things the signal flows from Pin 2, to the ECU, then will earth from there somewhere.

In our addition some of the flow travels firstly through the switch, then the jumper wire (or resistor), through the pot, and out to earth through Pin 3. (I`ve actually drawn it wrong above, showing it coming from Pin 3, through the switch and pot, then out to Pin 2. I`ll swap the Pin 2 and 3 annotations later.)

Clear as mud?